1. Field
Aspects of embodiments of the present invention relate to a secondary battery and a method of manufacturing the secondary battery.
2. Description of the Related Art
in recent years, as electronics and communication industries rapidly grow, a portable electronic device (such as a camcorder, a cellular phone or a notebook computer) is coming into wide use. This leads to the increased use of a secondary battery. The secondary battery is being used (utilized) for the portable electronic device as well as medium and large sized equipment, such as an electric tool requiring high output and high power, a vehicle, a boat, a space transportation system, a motorbike, a scooter or an air transportation vehicle.
Recently, a high-output secondary battery with high-energy density using (utilizing) a non-aqueous electrolyte is being developed. The above-mentioned high-output secondary battery forms a high-capacity secondary battery by connecting a plurality of secondary batteries to each other so as to be used in driving a motor of a device requiring high power, for example, an electric vehicle.
If a short circuit occurs in the secondary battery, an overcurrent flows in the secondary battery. The continuous flow of the overcurrent generates an excessive amount of heat, thus causing the bursting and/or ignition of the secondary battery. In order to solve the problem, a short-circuit portion and a vent portion may be provided on a cap plate. Thereby, if an internal pressure of the secondary battery exceeds a preset pressure, the short-circuit portion induces the short circuit, thus interrupting the flow of a current, and the vent portion is broken, thus discharging gas generated by the excessive amount of heat.
However, the related art is problematic in that the short-circuit portion and the vent portion are separately processed and then are welded to the cap plate, so that a manufacturing cost is high and productivity is low. Therefore, there are needs to conduct various types (kinds) of suitable research into a secondary battery that is capable of reducing a manufacturing cost and improving productivity.